# Homework H4.C - Fa22

Discussion

FOUR-STEP PLAN

Step 1: FBD - Draw a free body diagram of particle P. Note that the slot is smooth (no friction), and that the system moves in a horizontal plane (no influence of gravity).

Step 2: Newton - Recommended that you use a set of xy-coordinate axes attached to slotted arm. Resolve your forces into xy-components, and write down Newton's 2nd law for P in terms of its xy-components.

Step 3: Kinematics - It is recommended that you use the moving reference frame velocity and acceleration equations for point P, with the observer being attached to the slotted arm:
vP = vO + (vP/O)rel + ω x rP/O
aP = aO + (aP/O)rel + α x rP/O + 2ω x (vP/O)rel + ω x (ω x rP/O)
Along with the rigid body velocity and acceleration equations for link AP, you will be able to solve these equations for the xy-components of the acceleration of P.

Step 4: Solve - Combine your equations from Steps 2 and 3 to solve for the normal force acting on P by the slot and the force on P by link AP.

## 11 thoughts on “Homework H4.C - Fa22”

1. Drew Payne says:

When trying to relate the velocity of P to A, is there a way to calculate the angular velocity of AP?

1. Christian Charlson says:

I believe the angular velocity is given as omega.

2. Harrison Scott Booker says:

What I did was set up another equation relating velocity of P to O, allowing me to solve for the j component of the velocity of P, and I related the j components of the two different equations for the velocity of P.

2. Christian Charlson says:

How are we supposed to figure out what d_dot is since that would be the (vp/o)rel?

1. Quqi Zhang says:

so once you have the newton second law equation for particle B, and the moving reference frame equation for the acceleration of P. You could set both the acceleration that you got equals to each other, and from there you can get the tension and d dot

1. Quqi Zhang says:

I think that you would also need to link velocity and Acceleration equation for link AP.

3. Serigne Babacar Diagne says:

I think omega is the angular velocity of the slot OD not of the link AP

4. Serigne Babacar Diagne says:

Should we assume that the angular acceleration of the link AP is zero like that of the slot

1. Joshua Charles Sander says:

We can't assume that the angular acceleration of link AP is zero since we don't know anything about it. We only know angular acceleration of bar OP is zero because we are given that Omega is constant.